Script Interpreter Connection to Non-Standard Port

Last updated 2 days ago on 2026-02-09
Created 12 days ago on 2026-01-30

About

Detects the execution of a script interpreter followed by an outbound network connection to a raw IP address on a non-standard port. Many initial access scripts and malware implants connect directly to C2 or payload servers using non-standard ports to avoid detection.
Tags
Domain: EndpointOS: macOSUse Case: Threat DetectionTactic: Command and ControlTactic: ExecutionData Source: Elastic DefendLanguage: eql
Severity
medium
Risk Score
47
MITRE ATT&CK™

Command and Control (TA0011)(external, opens in a new tab or window)

Execution (TA0002)(external, opens in a new tab or window)

License
Elastic License v2(external, opens in a new tab or window)

Definition

Rule Type
Event Correlation Rule
Integration Pack
Prebuilt Security Detection Rules
Index Patterns
logs-endpoint.events.process-*logs-endpoint.events.network-*
Related Integrations

endpoint(external, opens in a new tab or window)

Query
text code block:
sequence by process.entity_id with maxspan=1m [process where host.os.type == "macos" and event.type == "start" and event.action == "exec" and (process.name like~ "python*" or process.name in ("node", "ruby")) and process.args_count == 2] [network where host.os.type == "macos" and event.type == "start" and (process.name like~ "python*" or process.name in ("node", "ruby")) and destination.domain == null and not destination.port in (443, 80, 53, 22, 25, 587, 465, 8080, 8089, 8200, 9200) and destination.port < 49152 and not cidrmatch(destination.ip, "240.0.0.0/4", "233.252.0.0/24", "224.0.0.0/4", "198.19.0.0/16", "192.18.0.0/15", "192.0.0.0/24", "10.0.0.0/8", "127.0.0.0/8", "169.254.0.0/16", "172.16.0.0/12", "192.0.2.0/24", "192.31.196.0/24", "192.52.193.0/24", "192.168.0.0/16", "192.88.99.0/24", "100.64.0.0/10", "192.175.48.0/24", "198.18.0.0/15", "198.51.100.0/24", "203.0.113.0/24", "::1", "FE80::/10", "FF00::/8")]

Install detection rules in Elastic Security

Detect Script Interpreter Connection to Non-Standard Port in the Elastic Security detection engine by installing this rule into your Elastic Stack.

To setup this rule, check out the installation guide for Prebuilt Security Detection Rules(external, opens in a new tab or window).